A field method for assessing borehole friction for directional well casing
A field method for assessing borehole friction for directional well casing
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DOI：
10.1016/0920-4105(88)90007-1
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发表时间：
1988-10
影响因子：
--
通讯作者：
E. Maidla;A. Wojtanowicz
中科院分区：
文献类型：
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作者：
E. Maidla;A. Wojtanowicz
开发了一种评估管柱与井眼之间井眼摩擦系数的现场程序。本研究的主要关注点是通过使用二维方法来研究和数学描述定向井中套管下入时的阻力。通过将计算的钩载荷与地面的实测载荷进行匹配，通过迭代计算得到井眼摩擦系数。计算井眼摩擦系数作为匹配的唯一值。本文研究了钩式载荷测量仪器的精度要求，并提出了满足精度要求的三种不同类型的设备。通过引入拖重比的概念，论述了机械摩擦对吊钩载荷的影响。结果表明，为保证方法的准确性，拖重比的最小要求值应为25%。统计分析表明，井眼摩擦系数的一个单一值可以代表井眼。研究结果表明，该模型可用于预测定向井套管柱的拉伸载荷。
A field procedure to evaluate the borehole friction factor between a pipe string and a borehole was developed. The primary concern of this research was to investigate and mathematically describe the drag associated with casing runs in directional wells through the use of the two-dimensional approach. The borehole friction factor was found, through an iterative procedure, by matching the calculated hook load to the measured one at the surface. The borehole friction factor was calculated as the unique value for the match.This study shows the necessary precision requirements for the hook load measurement instrumentation and presents three different types of equipment that meet accuracy demands. The significance of the mechanical friction effect on hook load was also addressed, by introducing the drag-weight ratio concept. It was found out that to assure accuracy of the method, the minimum required value of the drag-weight ratio should be 25%.The statistical analysis revealed that one single value of the borehole friction factor can represent the well.It was concluded in the study that the model can be used for prediction of tensional load of a casing string in a directional well.